That won't fix the problem. Because it's not that Marauders can't get strength... Marauders with 174 strength will deal less damage than Lancers with 120 so how will gear with +5 strength change that?
No, just no. No need to start making stuff up and hoping someone who actually knows better doesn't come along. That being said, stats being as worthless as they are.. 174 STR compared to 120 STR is only 5 more Attack. Factor in randomness of everything and it would be really hard to find a difference.

Marauders with 174 strength still do slightly more damage than gladiators with a ONE HAND weapon at HALF DELAY.
Only slightly? Lets not exaggerate here. Something is wrong with your MRD if it's only slightly.

but after watching videos on youtube of all our MRD weapon skills i notice they are all almost the same and quite boring....lancers getting a 6 fold attack - PGL with a 9 fold attack etc...What the hell happened with the MRD class
Nothing happened. LNC always had that attack they just never had an animation that showed it. PGL has always had Simian Thrash. IMO, multi hit WS doesn't seem right for a MRD. Lancer now has that animation for Chaos Thrust because it was absolute crap before and needed to be changed.

We have all single fold attacks that our weak and boring
MRD should have single fold attacks. Lets not forget that just about every MRD attacks can hit multiple enemies so its a pretty fair trade off. And you are doing something wrong if your are weak, I was able to do 1k+ before even hitting R40 on appropriate rank leve mobs. And as far as boring goes, every single melee class is full of boring, repetitive animation weapon skills, not just MRD. Each class pretty much has 2 that look fairly different and "cool". As MRDs you have Iron Tempest and Storm's Path. They don't look boring to me at all.

so my question is, should i quit MRD now and reroll lancer or archer for DD? Am i wasting my time
This is a problem a lot of MRDs have. They think they should be the best DD. Amazes me that a MRD can fill every single role in a party besides main healer, and they still find time to complain about wanting to be a better DD then everyone else. Archer does the amount of damage they do because 1) they can't do anything else, and 2) they shoot gil. An Archer can't main tank + do great damage on everything at the same time the way a GLA can. GLA can fill more roles then all the other melee, you shouldn't get to be the strongest as well.